Apparatus for generating an oscillatory motion

ABSTRACT

A fluid piston/cylinder mechanism for generating oscillatory motion consists of a cylinder having an inlet port in one end and outlet ports in its walls, uncovered when the piston is remote from that one end, and an outlet port for fluid in the piston, which can be closed to hinder flow of fluid from the cylinder when the piston is adjacent the said one end of the cylinder, but opens when the outlet ports in the walls of the cylinder are uncovered. The closure member for said port may be a freely moveable ball located in the cylinder.

United States Patent Paterson 51 Feb. I, 1972 [54] APPARATUS FOR GENERATING AN 1,294,061 2/1919 Dexter ..91/401 222 222 21225 2:122:

, ur [72] inventor: Donald MacDougal Paterson, London, En- 2,902,007 9/1959 Rockwell ..91/401 gland 3,361,036 1/1968 Harvey et al.. .91/401 [73] Assigneez Patemn Products Limited London, Em 3,397,619 8/1968 Sturtevant ..91/402 gland [22] Filed; July 23, 9 Primary ExaminerPaul E. Maslousky [21] A I N 746 891 Attorney-Cushman, Darby & Cushman [30] Foreign Application Priority Data [57] ABSTRACT A fluid piston/cylinder mechanism for generating oscillatory July 26, 1967 Great Britain ..34,366/67 motion consists of a cylinder having an in! port in one end and outlet ports in its walls, uncovered when the piston is [52] U.S.Cl .9l/S0, 99110 4 0 1, 991//244632, remote from hat one end and an outlet port for fluid in the piston, which can be closed to hinder flow of fluid from the 2; 4513? cylinder when the piston is adjacent the said one end of the 1 0 an cylinder, but opens when the outlet ports in the walls of the cylinder are uncovered. The closure member for said port may [56] References cued be a freely moveable ball located in the cylinder.

UNITED STATES PATENTS I 2,424,108 7/ 1947 Merten ..9l/50 6 Claims, 3 Drawing Figures APPARATUS FOR GENERATING AN OSCILLATORY MOTION The present invention relates to apparatus for generating an oscillatory motion, and is of particular value in imparting oscillatory motion to apparatus in whole or in part immersed in a liquid medium. The invention finds particular application in the field of liquid-processing apparatus, e.g., where articles to be processed are held in a frame mounted in a tank, and the frame is rocked in order to increase the evenness of action of the processing liquid and avoid the incidence of inadequately processed areas where the articles to be processed are, when static, lying against the frame.

A specific application of such apparatus is in the processing of photographic materials, e.g., in developing, fixing or like procedures and, in particular, in the washing of photographic prints.

According to the present invention there is provided apparatus for generating oscillatory motion which comprises a hollow cylinder, a piston adapted to move within the said cylinder from a rearward position to a forward position and being biased towards the forward position, the forward end of the cylinder having an inlet port for fluid, the wall of the cylinder having an outlet port for fluid which is uncovered only when the piston is in its rearward position, and the piston having an inlet port for fluid in its forward face and an outlet port for fluid at its rearward end, there being further provided a freely movable closure means for the piston inlet port which is adapted to eflect such closure under pressure applied thereto by fluid flowing through the cylinder inlet port.

In a preferred form of the invention the said closure means is a freely movable ball held captive between the forward end of the piston and the forward end of the cylinder, the ball being able to be held against the piston inlet port by the pressure of the stream of fluid flowing through the cylinder inlet port into the cylinder, but dislodging from such position when the said pressure is reduced.

The use of a freely movable ball closure which is operated by the flow of fluid itself allows the apparatus to function independently of external force fields, i.e., the action of the force of gravity on the components does not affect the working of the apparatus.

Preferably the cylinder fluid inlet comprises a nozzle mounted axially with respect to the cylinder and of sufficient length to provide a directional flow of fluid into the cylinder. The nozzle is preferably tapered inwardly towards the cylinder. The piston fluid inlet preferably comprises, where a captive ball closure means is used, a circular port positioned on the axis of the cylinder and most preferably standing out from the forward face of the piston.

By way of example, the invention will be described with reference to the accompanying drawings in which:

FIGS. 1 and 2 are cross-sectional views of an apparatus according to the invention for generating oscillatory motion, in two different positions.

FIG. 3 is a perspective view of part of photographic material rinsing apparatus embodying apparatus for generating oscillatory motion according to the present invention.

Referring to FIGS. 1 and 2, the apparatus comprises a fixed cylinder 1 and movable hollow cylindrical piston 2. Within the cylinder is a free ball 3. The cylinder is provided with an inlet diameter of bill 795 mm. internal diameter of cylinder 8.72 mm. external diameter of piston 7.14 mm.

diameter of inlet port in cylinder wall internal diameter of inlet nozzle in piston face i 5.55 mm. external diameter of inlet nozzle in piston face 6.35 mm. length of inlet nozzle 4 12.7 mm. taper of nozzle 0.9'

In use, fluid is fed at a constant rate through nozzle 4 into the cylinder. Ball 3 is held by the stream of fluid against nozzle 6 and the piston is thus urged from the cylinder as more fluid enters through nozzle 4. When the piston has moved sufficiently to uncover the ports 5, fluid flows through the cylinder and out through those ports. The fluid flow displaces ball 3 from noule 6 and throws it back against the end wall of cylinder 1, thus allowing water to escape from the cylinder via nozzle 6. The piston now, under the action of its bias toward the forward end of the cylinder, moves towards that forward end, fluid passing into the cylinder via nozzle 4 and leaving the cylinder at first by both ports 5 and nozzle 6 and then via nozzle 6 only. As the piston nears the end of its travel, nozzle 6 approaches and finally is closed by the ball 3. Since water cannot now escape from the cylinder, the piston is urged from the cylinder until ports 5 are again uncovered. The process thus repeats itself constantly, and the piston 2 undergoes an oscillatory motion. H

FIG. 3 shows the apparatus of FIG. 1 and 2 installed in a photographic print washing apparatus. The print-washing apparatus comprises an open-topped tank 7 containing a frame 8 pivotally mounted at its base so as to rock about an axis parallel to and displaced to one side from the central long axi's of the tank so as to be biased in the direction of the arrow by its weight. Mounted in a reservoir 9 is an apparatus for generating oscillatory motion numbered as described above. Water may be fed to reservoir 9 by means of inlet pipe 10. The frame 8 bears against the open end of piston 2, which projects from cylinder 1, by means of an arm 11 fixed to the frame 8 and thereby biases the piston 2 in the same direction as frame 8.

In use, the tank 1 is first filled and water is then fed into reservoir 9 via pipe 10, and through nozzle 4. The apparatus acts as described above to cause piston 2, and thus frame 8, to oscillate. The extra water added via the cylinder 2 is compensated by an overflow from the tank (not shown) which serves to maintain the water at a constant level. If desired, water may also be continuously supplied tothe tank independently of the oscillatory motion generator, in order to increase the rate of water flow through the tank, and thereby the efficiency of the rinsing.

While the apparatus of the invention preferably employs a ball closure as described, it will be appreciated that alternatives may be used. Thus for example the closure may consist of a hinged plate which in the absence of fluid pressure will fall under gravity, or be spring urged, away from the closure position, but which will be brought to closure position by the internal configuration of the cylinder at its forward end, and held closed by the pressure of the stream of fluid entering the cylinder inlet port until the cylinder outlet port is uncovered, when that pressure will fall away.

I claim as my invention:

1. Apparatus for generating oscillatory motion which com prises a hollow cylinder, a piston adapted to move within the said cylinder from a rearward position to a forward position and means for biasing said piston towards the forward position, the forward end of the cylinder having a continuously open inlet port for continuous supply of fluid under pressure, the wall of the cylinder having an outlet port for fluid which is uncovered only when the piston is in its rearward position, and the piston having an inlet port for fluid in its forward face and an outlet port for fluid at its rearward end, there being further provided a freely movable closure means for the piston inlet port, said closure means being freely movable in the area between said cylinder inlet port and the inlet port for said piston and being movable into contact with the piston inlet port to effect closure thereof only under pressure applied thereto by fluid flowing through the cylinder inlet port.

2. Apparatus according to claim I wherein said closure means is a freely movable ball held captive between the forward end of the piston and the forward end of the cylinder.

inlet comprises a nozzle mounted axially with respect to the cylinder and of sufficient length to provide a directional flow of fluid into the cylinder.

6. Apparatus according to claim 5 wherein said nozzle is tapered inwardly toward the cylinder. 

1. Apparatus for generating oscillatory motion which comprises a hollow cylinder, a piston adapted to move within the said cylinder from a rearward position to a forward position and means for biasing said piston towards the forward position, the forward end of the cylinder having a continuously open inlet port for continuous supply of fluid under pressure, the wall of the cylinder having an outlet port for fluid which is uncovered only when the piston is in its rearward position, and the piston having an inlet port for fluid in its forward face and an outlet port for fluid at its rearward end, there being further provided a freely movable closure means for the piston inlet port, said closure means being freely movable in the area between said cylinder inlet port and the inlet port for said piston and being movable into contact with the piston inlet port to effect closure thereof only under pressure applied thereto by fluid flowing through the cylinder inlet port.
 2. Apparatus according to claim 1 wherein said closure means is a freely movable ball held captive between the forward end of the piston and the forward end of the cylinder.
 3. Apparatus according to claim 1 wherein the piston fluid inlet comprises a circular port positioned on the axis of the cylinder.
 4. Apparatus according to claim 3 wherein said circular port stands out from the face of the piston.
 5. Apparatus according to claim 1 wherein the cylinder fluid inlet comprises a nozzle mounted axially with respect to the cylinder and of sufficient length to provide a directional flow of fluid into the cylinder.
 6. Apparatus according to claim 5 wherein said nozzle is tapered inwardly toward the cylinder. 